DE102017214826A1 - INJECTOR CONTROL DEVICE AND INJECTOR CONTROL METHOD - Google Patents

Abstract

A target injector opening period is calculated based on a target fuel injection amount, and an injector 2 is controlled by a power supply control unit 51 in accordance with an injector drive period detected based on the target injector open period. An actual valve closing delay period is calculated based on an output waveform of the injector 2 at that time, and a difference between an actual valve closing delay period and a valve closing delay period calculated from the target injector valve opening period is learned. Then, the injector drive period is corrected by feedback control using a result of this learning.

Description

BACKGROUND OF THE INVENTION

Field of the invention

The present invention relates to an injector control device and an injector control method.

Description of Related Art

In recent years, regulation of soot particles contained in the exhaust gas has become more restrictive. An internal combustion engine configured to inject gasoline into a cylinder generates a relatively large amount of soot particles. Therefore, instead of decreasing a one-time fuel injection amount, a method involving dividing and repeating gasoline injection is proposed, thereby completing the regulation of soot particles.

In order to reduce the injection quantity once, only the drive period of the injector needs to be lowered. However, it is not easy to precisely control a small injection amount as in WO 2013/191267 A1 disclosed. To solve this problem is in WO 2013/191267 A1 has proposed a control device configured to calculate a derivative of second object data of a solenoid terminal voltage of the injector after an end of the power supply to detect a maximum value of the derivative of second object data to thereby detect an actual valve closing timing.

Moreover, Japanese Patent Laid-Open Publication No. 2015-151871 discloses a control method which involves detecting and learning a valve closing timing of an injector, thereby correcting a current supply period to a coil of the injector. As the temperature of the coil of the injector changes, an electrical resistance of the coil changes in response to the temperature change. As a result, a variation in a Ti-Q characteristic caused by the temperature of the coil is generated, indicating a relationship between a current supply period Ti to the coil and an injection amount q of the injector. In Japanese Patent Laid-Open Publication No. 2015-151871, an actual injection amount of the injector is detected and learned in consideration of this variation, and the current supply period to the coil of the injector is corrected based on the past detection values.

When the injector is controlled according to the current supply period to the solenoid, which is calculated based on the target fuel injection amount, the fuel injection amount varies due to the individual difference of the injector.

However, in WO 2013/191267 A1 Although the valve closing timing detection method is disclosed, no specific disclosure regarding the current supply period correcting method is given to the solenoid of the injector.

Moreover, the control method disclosed in Japanese Patent Laid-Open Publication No. 2015-151871 adopts the operation variation due to the temperature change in the coil of the injector and is configured to correct a degradation in repeatability caused by operation variation due to the temperature change in the coil of the injector Use is caused. Thus, the control method disclosed in Japanese Laid-Open Patent Publication No. 2015-151871 does not correct the current supply period to the coil so as to achieve a valve opening period corresponding to a target fuel injection amount that is a reference characteristic. Further, Japanese Laid-Open Patent Publication No. 2015-151871 does not take individual variation due to production variation of the injector with respect to, for example, weights and play of a spring, a spool, and a needle of the injector, and therefore, the control method disclosed in Japanese Patent Laid-Open Publication No. 2015-151871 do not correct the variation of the fuel injection amount due to the individual variation of the injector.

SUMMARY OF THE INVENTION

The present invention has been made in view of the above-mentioned problems, and therefore provides an injector control apparatus and an injector control method capable of decreasing a variation of a fuel injection amount due to an individual variation of an injector.

According to an embodiment of the present invention, there is provided an injector control apparatus configured to control an injector, the injector including: a fuel passage configured to allow a fuel to be injected for an internal combustion engine to pass; a needle valve configured to separate from a valve seat provided at a fuel injection port of the fuel passage to open the fuel passage and to abut against the valve seat to close the fuel passage; and a solenoid configured to attract the needle valve in a valve opening direction when a current is supplied to the solenoid, the injector control apparatus including: a target injection amount calculating unit configured to inject a target injection amount of the one injected by the injector To calculate fuel in response to an operating condition of the internal combustion engine;
a target injector valve opening period calculating unit configured to calculate a target injector valve opening period corresponding to the target injection amount based on the target injection amount, in accordance with characteristic data of an injector valve opening period with respect to a fuel injection amount; an injector valve opening delay period calculating unit configured to calculate, based on the target injector valve opening period, a valve opening delay period from a power supply start timing of the solenoid to a valve opening timing at which the valve seat and the needle valve of the injector separate from each other; in accordance with characteristic data on the valve opening delay period with respect to the injector valve opening period; a post-learning injector valve closing delay period calculating unit configured, based on the target injector valve opening period, a valve closing delay period from a power supply end timing of the solenoid to a valve closing timing to which the valve seat and the needle valve of the injector abut each other To calculate a match with a learning map having the injector valve opening period as at least one axis and storing a learned value of the valve closing delay period; an injector drive period calculating unit configured to calculate a current supply period of the solenoid based on the target injector valve opening period, the valve opening delay period, and the valve-shake delay period; a power supply control unit configured to supply the current to the solenoid of the injector in accordance with the power supply period to the solenoid to thereby drive the injector; an injector valve closing timing calculating unit configured to detect an actual valve closing timing to which the valve seat and the needle valve actually abut one another based on a driving voltage waveform of the solenoid when the power supply control unit controls the injector based on the power supply period of the solenoid Solenoids drives; an injector actual valve closing delay period calculating unit configured to calculate an actual valve closing delay period from the power supply end timing of the solenoid to the actual valve closing timing, based on the actual valve closing timing, an actual power supply start timing of the solenoid and an actual power supply period to the solenoid ; an injector valve closing delay period difference calculating unit configured to calculate a valve closing delay period difference representing a difference between the valve closing delay period calculated by the post-learning injector valve closing delay period calculating unit and the injector valve closing timing Arithmetic unit calculated actual valve closing delay period; and an injector valve closing delay period learning value calculating unit configured to update the learned value of the valve closing delay period in the learning map based on the valve closing delay period difference, wherein the post-learning injector valve closing delay period calculating unit configures is to use, at a next calculation timing, the learning map in which the learned value of the valve closing delay period updated by the injector valve closing delay period learning value calculating unit is stored thereby to calculate the valve closing delay period.

The injector control apparatus according to the present invention is configured to learn the characteristic of the valve closing delay period of the injector and to use the learning result for controlling the drive period of the injector according to the target fuel injection amount, whereby the variation of the fuel injection amount due to the individual variation of the injector decreases ,

list of figures

• 1 FIG. 12 is a schematic cross-sectional view illustrating a configuration of an injector to be controlled by an injector control apparatus according to a first embodiment of the present invention. FIG.
• 2 Fig. 10 is a block diagram for illustrating an internal configuration of the injector control apparatus according to the first embodiment of the present invention.
• 3 FIG. 16 is a hardware configuration diagram for illustrating a hardware configuration of the injector control apparatus according to the first embodiment of the present invention. FIG.
• 4 FIG. 10 is a flowchart for illustrating a flow of injector-valve-closing delay period learning value computation processing in the injector control apparatus according to the first embodiment of the present invention. FIG.
• 5 FIG. 15 is a diagram for illustrating a learning map of an injector-closing delay period learning value used in the injector control apparatus according to the first embodiment of the present invention.
• 6 FIG. 10 is a time chart for illustrating a relationship between the injector drive period and an injector valve opening period in the injector control apparatus according to the first embodiment of the present invention. FIG.
• 7 FIG. 14 is a flowchart illustrating a flow of processing by the injector control apparatus according to the first embodiment of the present invention. FIG.

DESCRIPTION OF THE EMBODIMENTS

First embodiment

Now, a description will be made of an injector control device (hereinafter simply referred to as a control device 50 ) according to a first embodiment of the present invention, with reference to the drawings. According to the first embodiment, the control apparatus is constructed 50 a part of a control device for an internal combustion engine, and a drive circuit for injectors 2 is in the control device 50 built-in. The drive circuit for the injectors 2 can be independent of the control device 50 be constructed. According to the first embodiment, the control device 50 configured the injectors 2 that are provided for the internal combustion engine of a vehicle to control.

First, a description will be given of a configuration of the injector 2 given. 1 Fig. 12 is a cross-sectional view schematically illustrating the structure of the injector 2 according to the first embodiment. As in 1 Illustrated, the injector includes 2 a valve seat 10 provided at an injection port of a fuel passage, a needle valve 11 configured to open or close the fuel passage and a solenoid 12 that is configured, the needle valve 11 to propel to open or close the fuel passage. The needle valve 11 is configured to move to a valve closing direction X1 and the valve seat 10 whereby the fuel passage is brought into a closed state. In addition, the needle valve 11 configured to move to a valve opening direction X2 and the valve seat 10 to separate, whereby the fuel passage is brought into an open state.

The injector 2 further includes a movable element 14 , a zero position spring 15 and a mainspring 13 , The moving element 14 is made of a magnetic substance and is configured when a current is applied to the solenoid 12 is supplied to the valve opening direction X2 by a magnetic force which is generated by the power supply. The zero position spring 15 is on the valve closing direction X1 side with respect to the movable member 14 intended. The zero position spring 15 is configured, the movable element 14 to energize the valve opening direction X2. The needle valve 11 includes a flange 18 , The flange 18 is on an upper end side with respect to a center in an axial direction of the needle valve 11 provided. The flange 18 may be at an upper end in the valve opening direction X2 of the needle valve 11 be provided. The main spring 13 is on the valve opening direction X2 side with respect to the flange 18 arranged. The main spring 13 is configured, the needle valve 11 to energize the valve closing direction X1. An energizing force of the mainspring 13 is stronger than an energizing force of the zero position spring 15 ,

The needle valve 11 is constructed by an element in a rod shape. A lower end of the needle valve 11 namely, the tip in the valve closing direction X1 is tapered toward a point. If the current is not the solenoid 12 is fed, moves the needle valve 11 to the valve closing direction X1 by the energizing force of the main spring 13 and a fuel pressure. When the tip of the needle valve 11 against the injection port of the valve seat 10 , closes the tip of the needle valve 11 the injection port and the fuel passage is brought to the closed state. The injector 2 includes a magnetic core 16 and a housing 17 , The housing 17 is formed in a tubular shape and is configured internally the corresponding components of the injector 2 to store. The solenoid 12 is through one on one Spool core wound cylindrical coil constructed. The magnetic core 16 is between the solenoid 12 and the mainspring 13 arranged.

The moving element 14 is made of the magnetic substance brought into a hollow cylindrical shape. Both an upper end and a lower end of the movable element 14 are open. The needle valve 11 is arranged so that it is the cavity of the movable element 14 happens. The moving element 14 is on the valve closing direction X1 side with respect to the flange 18 arranged. The moving element 14 and the needle valve 11 can move relative to each other. The zero position spring 15 is on the valve closing direction X1 side with respect to the movable member 14 arranged and is configured, the movable element 14 in relation to the housing 17 to energize the valve opening direction X2.

In addition, the surface layer is 14 on the valve closing direction X1 side with respect to the magnetic core 16 arranged. When the current is the solenoid 12 by the control of the control device 50 is supplied, the movable element 14 to the valve opening direction X2 side by that in the magnetic core 16 generated magnetic force attracted. When the current is the solenoid 12 is supplied, the movable element 14 to the valve opening direction X2 by the energizing force of the zero-position spring 15 and in the magnetic core 16 by supplying power to the solenoid 12 moved in this way generated magnetic force. On this occasion, the movable element pushes 14 against the flange 18 of the needle valve 11 , causing the flange 18 is shifted in the valve opening direction X2. As a result, move the movable element 14 and the needle valve 11 integral in the valve opening direction X2. Thus, if the tip of the needle valve 11 from the valve seat 10 deviates in the valve opening direction X2, the injection port opens and the fuel passage is brought into the open state.

When the solenoid 12 by the control of the control device 50 from the power supply state to the non-power supply state, the attraction force disappears to the valve opening direction X2 side passing through the movable element 14 by the magnetic force of the magnetic core 16 is applied, and moves the needle valve 11 to the valve closing direction X1 by the energizing force to the valve closing direction X1 of the main spring 13 , On this occasion, the flange pushes 18 of the needle valve 11 the movable element 14 down to the valve closing direction X1 and move the needle valve 11 and the movable element 14 integral with the valve closing direction X1. When the tip of the needle valve 11 with the valve seat 10 as a result, the movement of the needle valve stops 11 but separates the movable element 14 from the flange 18 and continues to move to the valve closing direction X1.

Subsequently, the movable element slows down 14 by the Energetisierungskraft to the valve opening direction X2 by the zero-position spring 15 , then moves in the valve opening direction X2 and pushes against the flange again 18 on to stop.

Now, a description will be made of the control device 50 given. 2 FIG. 10 is a block diagram for illustrating a configuration of the control device. FIG 50 , As in 2 illustrates, includes the control device 50 a power supply control unit 51 , a target injection quantity calculating unit 52 , a target injector valve opening period calculating unit 53 , an injector valve opening delay period calculating unit 54 , a post-learning injector valve closing delay period calculating unit 55, an injector valve closing timing calculating unit 56 , an injector actual valve closing delay period calculating unit 57, an injector valve closing delay period learning value calculating unit 59, and an injector driving period calculating unit 60 ,

The respective units 51 to 60 the control device 50 be through a hardware circuit of the control device 50 achieved. Specifically, as in 3 illustrates, includes the control device 50 as the hardware circuit, a calculation processing device 90 by a central processing unit (CPU), a storage device 91 configured to transfer data to or from the computational processing device 90 to send or receive an input circuit 92 that is configured to receive signals from outside the computing processing device 90 and an output circuit 93 configured to receive signals from the computational processing device 90 to spend to the outside. The storage device 91 includes a random access memory (RAM) configured to receive data from the computational processing device 90 and a read-only memory (ROM) configured to receive data from the arithmetic-processing device 90 can be read out. The input circuit 92 includes A / D converters connected to various sensors and switches and configured to convert output signals from those sensors and switches to digital signals to thereby receive the digital signals from the computational processing device 90 enter. The output circuit 93 includes Drive circuits connected to electrical loads and configured are control signals from the arithmetic processing device 90 to spend on those electrical loads.

Respective functions of the respective units 51 to 60 the control device 50 from 2 are by the arithmetic processing device 90 that executes software scores, namely one in the ROM of the storage device 91 stored program, and with the storage device 91 cooperating, the input circuit 92 , the output circuit 93 and other hardware (not shown) of the controller 50 , Moreover, a plurality of CPUs and a plurality of memories may cooperate with each other to perform the above-mentioned functions of the respective units 51 to 60 the control device 50 perform.

According to the first embodiment, the input circuit includes 92 a terminal voltage detection circuit connected to a positive terminal and a negative terminal of the solenoid 12 of the injector 2 is connected and configured, an output signal proportional to a terminal voltage between the positive terminal and the negative terminal of the solenoid 12 issue. The output signal from the terminal voltage detection circuit is applied to the arithmetic processing device 90 entered via the A / D converter. The terminal voltage detection circuit is constructed by a resistor or a comparator.

Further, various sensors (not shown) for detecting an operating state of the internal combustion engine, for example, an air flow sensor, a throttle opening degree sensor, and a crank angle sensor with the input circuit 92 connected.

The output circuit 93 includes an injector drive circuit connected to the positive pole terminal and the negative pole terminal of the solenoid 12 of the injector 2 is connected, and configured to supply power to the solenoid 12 of the injector 2 to control. The injector drive circuit is constructed by a switching element configured to supply the power of the solenoid 12 To turn ON / OFF. Although not shown, various actuators for controlling the internal combustion engine, such as a throttle valve drive motor and an ignition coil, are connected to the output circuit 93 connected. According to the first embodiment, a plurality of injectors 2 for the internal combustion engine, and are the voltage detection circuit and the injector drive circuit for each of the injectors 2 intended. The following is a description of a case where the number of injectors 2 is one for the sake of simplicity of description. Even in a case where a plurality of injectors 2 are provided, an operation is the same as that in the case where the number of injectors 2 One is, and thus the description is omitted here.

The control device 50 is configured to calculate a fuel injection amount and an ignition timing based on the output signals input from the various sensors and the drive of the injector 2 and control the ignition coil as a base control. In addition, the control device 50 configured to detect an intake air amount of the internal combustion engine based on the output signals from various sensors including the air flow sensor and to detect a crank angle speed and a crank angle of the engine based on the output signal of the crank angle sensor.

Now a description of the corresponding units will be given 51 to 60 the in 2 illustrated control device 50 given.

<Power Supply Control Unit 51>

The power supply control unit 51 is configured to supply a current to the solenoid 12 of the injector 2 supply. The power supply control unit 51 is configured, an instruction of a drive period Td_on of the injector 2 generated by the injector drive period calculating unit 60 is calculated, namely an injection pulse width, the injector 2 granted. The drive period Td on, that is, the injection pulse width, means a current supply period to the solenoid 12 , The injection pulse width may be one of a plurality of divisions of an injection pulse width. The power supply control unit 51 is configured to turn on a first injection pulse signal at an injection timing set at the crank angle that is set in advance for instructing the injector drive circuit to execute the drive during a period of the injection pulse width, whereby the current flows to the solenoid 12 is supplied in this way. The injector drive circuit is configured to switch one or a plurality of switching elements ON / OFF based on the injection pulse signal. The power supply control unit 51 is configured, a actual power supply start timing Tstart and the drive period Td_on in the RAM of the storage device 91 save.

<Target injection amount computing unit 52>

The target injection quantity computing unit 52 is configured, a fuel injection amount of the injector 2 for calculating a target air-fuel ratio, which is set in advance in response to the operating state of the internal combustion engine. The operating state of the internal combustion engine includes the intake air amount detected by the air flow sensor. Moreover, as the operating state of the internal combustion engine in addition to the intake air amount, for example, the throttle opening degree detected by the throttle opening degree sensor or the crank angle detected by the crank angle sensor may be mentioned, and those parameters may be used.

<Target injector valve opening period calculating unit 53>

The target injector valve opening period calculating unit 53 is configured characteristic data for an injector valve opening period in advance in the ROM of the storage device 91 to use the target injector valve opening period Ttgt according to the target injection quantity calculating unit 52 calculate calculated target fuel injection quantity. In other words, for example, a lookup table and a characteristic map for defining in advance a correspondence between the target fuel injection amount and the target injector valve opening period in the ROM of the storage device 91 and is the target injector valve opening period calculating unit 53 configured to the target injector valve opening period according to the by the target injection amount computing unit 52 calculated target fuel injection amount, in accordance with the look-up table or the characteristic map. On this occasion, the target injector valve opening period means a target value of a period from a timing of the valve opening timing to which the valve seat 10 and the check valve 11 of the injector 2 to separate from each other until a time of the valve closing timing to which the valve seat 10 and the needle valve 11 of the injector 2 abut each other. Such a description that the characteristic data is stored in advance in the ROM in the storage device 91 are given, but the characteristic data can be stored in the RAM of the storage device 91 get saved.

<Injector valve opening delay period calculating unit 54>

The injector valve opening delay period calculating unit 54 is configured, characteristics data to an injector valve opening delay period with respect to a pre-ROM in the memory device 91 to use a stored desired injector valve opening period to calculate an injector valve opening delay period Ton with respect to the target injector valve opening period Ttgt, which is determined by the target injector valve opening period calculating unit 53 is calculated. In other words, for example, a lookup table or a characteristic map for defining in advance a correspondence between the target injector valve opening period and the injector valve opening delay period in the storage device 91 stored in advance and is the injector valve opening delay period calculating unit 54 configured, the injector valve opening delay period Ton with respect to the target injector valve opening period Ttgt, by the target injector valve opening period computing unit 53 is calculated according to the look-up table or the characteristic map. On this occasion, the valve opening delay period Ton is a period from the time of the power supply start timing Tstart of the solenoid 12 until the timing of a valve opening timing to which the valve seat 10 and the needle valve 11 of the injector 2 separate from each other. Such a description that the characteristic data is stored in advance in the ROM of the storage device 91 is stored, but the characteristic data can be stored in the RAM.

<Post-Learn Injector-Valve-Close Delay Period-Arithmetic Unit 55>

The post-learning injector valve closing delay period calculating unit 55 is configured to set the post-learning injector valve closing delay period with respect to an injector valve opening period in one in the RAM of the storage device 91 stored learning map based on the target injector valve opening period calculating unit 53 calculated target injector valve opening period Ttgt to determine a post-learning injector valve closing delay period Tadj with respect to the target injector valve opening period Ttgt. The post-learn injector valve closing delay period Tadj im, in the RAM of the memory device 91 stored learning map is an injector valve closing delay period Tadj, which is calculated by the injector valve closing delay period learning value calculation unit 59, which will be described later, and is a learning value stored in the learning map. On this occasion, the valve closing delay period Tadj is a period from a time of a power supply end timing of the information providing system 1 until solenoids 12 to a timing of the valve closing timing to which the valve seat 10 and the needle valve 11 of the injector 2 abut each other. On this occasion, if the individual variation of the injector 2 does not exist, the valve closing delay period Tadj passes at a period from a timing of the current supply end timing of the solenoid 12 until the timing of the end timing of the target injector valve opening period Ttgt. However, if a variation in the valve-closing characteristic of the injector 2 due to a manufacturing variation or a secular change in the injector 2 is generated, the valve closing delay period Tadj does not match the period, and an injector valve closing delay period difference Tdif described later is generated.

<Injector valve closing timing calculating unit 56>

The injector valve closing timing calculating unit 56 is converged, an actual valve closing timing Tclose of the injector 2 to calculate. As a calculation method, for example, a driving voltage waveform of the solenoid 12 detected when the solenoid 12 the drive period Td_on of the injector 2 is long driven calculated by the injector drive period calculating unit 60 , and a time at which the tip of the needle valve 11 actually abuts against the injection port which is in the valve seat 10 is provided, is determined from this drive voltage waveform as the actual valve closing timing Tclose. Alternatively, as another computing method, for example, a method that takes into account a change in acceleration of the movable member 14 when the needle valve 11 with the valve seat 10 collides detecting change in acceleration as a change in one in the voltage between the terminals of the solenoid 12 induced electromotive force, and determining a time point at which a second-order derivative of the voltage between the terminals becomes maximum, as the actual valve closing timing Tclose of the needle valve 11 considered, conceivable, as in WO 2013/191267 A1 disclosed. It is understood that other methods can be used.

<Injector actual valve closing delay period calculating unit 57>

The injector actual valve closing delay period calculating unit 57 is configured to calculate an injector actual valve closing delay period Tadj_real based on the injection valve closing timing calculation unit 56 calculated actual valve closing timing Tclose and the power supply start timing Tstart and the drive period Td_on stored in advance in the storage device 91 , Specifically, an injector actual valve closing delay period Tadj_real is determined by the following equation. $$\text{Tadj\_real}=\left(\text{Tclose}-\text{Tstart}\right)-\text{Td\_on}$$

<Injector valve closing delay period difference calculating unit 58>

The injector valve closing delay period difference calculating unit 58 is configured to calculate a difference Tdif between the injector actual valve closing delay period Tadj_real calculated by the injector actual valve closing delay period calculating unit 57 and the post-learning injector valve closing delay period Tadj calculated by the post-learning injector Valve closing delay period calculating unit 55, to calculate.

<Injector valve closing delay period learning value calculating unit 59>

The injector valve closing delay period learning value calculating unit 59 is configured to use the difference Tdif calculated by the injector valve closing delay period difference calculating unit 58 to determine the learning value of the injector valve closing delay period Tadj in the RAM of the storage device 91 to update the saved learning map. In the learning map, the learning value of the injector valve closing delay period Tadj is stored while the target injector valve opening period is set as at least one learning axis. The number of learning axes may be one or more. The learning axes may be two axes which are the target injector valve opening period Ttgt and a battery voltage Vb. Alternatively, the number of axes may be at least three. Examples of other learning axes will be described later. The injector valve closing delay period learning value calculating unit 59 is configured to update the learning value according to the operating condition used in the current learning when the learning value is updated in the learning map. In other words, the target injector valve opening period is set to the learning axis on this occasion, and thus the learning value corresponding to the target injector valve opening period used in the current learning is updated in the learning map when the learning value is updated. In this way, the operating condition used for the learning is set to the learning axis in the learning map and the learning value is stored while being associated with the learning axis. The learned value is used as the injector valve closing delay period for the next calculation timing by the post-learning injector valve closing delay period calculating unit 55. The learning value does not exist at the calculation timing at the first time in which the learning has not yet been performed even once, and an initial value of the injector valve closing delay period thus becomes in the ROM of the memory device 91 saved in advance and used the first time. Hereinafter, the learning value stored in the learning map is referred to as the post-learning injector-valve-closing delay period Tadj. The battery is usually in the vicinity of the control device 50 arranged and used as a power supply for the control device 50 and a drive power supply used for the injectors.

4 FIG. 10 is a flowchart illustrating a processing flow by the injector valve closing timing calculating unit. FIG 56 , the injector actual valve closing delay period calculating unit 57, the injector valve closing delay period difference calculating unit 58, and the injector valve closing delay period learning value calculating unit 59. When the injection of the injector 2 is executed, the processing of the flowchart of 4 ,

First, in step S01, the injector valve closing timing calculation processing in the injector valve closing timing calculating unit 56 executed and the actual valve closing timing Tclose of the injector 2 certainly. As the calculation method for the actual valve closing timing Tclose, any one of the above-mentioned methods may be executed.

Then, in step S02, the injector actual-valve closing delay period calculating unit 57 calculates the injector-actual-value closing delay period Tadj_real based on the injector valve closing timing Tclose detected in step S01 and the actual power supply starting timing Tstart and that in the storage device 91 Preset drive period Td_on.

Then, in step S03, the injector valve closing delay period difference calculating unit 58 calculates the injector valve closing delay period difference Tdif, which is the difference between the injector actual valve closing delay period Tadj_real and 57 of the post-injector valve closing delay period Tadj, based on the injector actual valve closing delay period Tadj_real, which is detected in step S02 and the post-learning injector valve closing delay period Tadj calculated based on the target injector valve opening period Ttgt in the post-learning injector valve closing delay period calculating unit 55.

Then, in step S04, the injector valve closing delay period learning value calculating unit 59 determines whether or not the injector valve closing delay period difference Tdif falls within a learning range Trange previously in the storage device 91 is stored. Specifically, it is determined whether the absolute value of the injector valve closing delay period difference Tdif is equal to or less than a threshold T_range. In other words, the learning range Trange is a range from -T_range to T_range. When the injector valve closing delay period difference Tdif is determined to be in the learning area Trange, that is, "Yes" in step S04, the processing proceeds to step S05.

$$Table\_off\_d\left[V+1\right]\left[T\right]=Table\_off\_d\left[V+1\right]\left[T\right]+K_{lrn}\times Tadj\_r\nu \times \left(1-Tadj\_rt\right)\times Tdif$$

$$Table\_off\_d\left[V\right]\left[T+1\right]=Table\_off\_d\left[V\right]\left[T+1\right]+K_{lrn}\times \left(1-Tadj\_r\nu \right)\times Tadj\_rt\times Tdif$$

$$Table\_off\_d\left[V+1\right]\left[T+1\right]=Table\_off\_d\left[V+1\right]\left[T+1\right]+K_{lrn}\times Tadj\_r\nu \times Tadj\_rt\times Tdif$$

In step S05, the processing of reflecting the injector valve closing delay period difference Tdif to the injector valve closing delay period learning map in the injector valve closing delay period learning value calculating unit 59 is executed. In 5 For example, an example of the learning map of a case where the learning axes for the injector valve closing delay period are set to the axes of the target injector valve opening period Ttgt and the battery voltage Vb and a reflection coefficient to the learning value Clern is illustrated. Corresponding elements are calculated according to the following equations. The reflection coefficient is usually a value less than 1, and is preferably about 0.5. For example, if the reflection coefficient is 0.5, half the difference from the current numerical value of the learning value is reflected. Even if the difference changes rapidly, a rapid change in the learning value can be suppressed by multiplying the difference by the reflection coefficient in this manner, and a variation of the operating state caused by the rapid change of the learning value can thus be reduced. $$Table\_Off\_d\left[V\right]\left[T\right]=Table\_Off\_d\left[V\right]\left[T\right]+K_{lrn}\times \left(1-Tadj\_r\nu \right)\times \left(1-Tadj\_rt\right)\times Tdif$$

$$Table\_Off\_d\left[V+1\right]\left[T\right]=Table\_Off\_d\left[V+1\right]\left[T\right]+K_{lrn}\times Tadj\_r\nu \times \left(1-Tadj\_rt\right)\times Tdif$$

$$Table\_Off\_d\left[V\right]\left[T+1\right]=Table\_Off\_d\left[V\right]\left[T+1\right]+K_{lrn}\times \left(1-Tadj\_r\nu \right)\times Tadj\_rt\times Tdif$$

$$Table\_Off\_d\left[V+1\right]\left[T+1\right]=Table\_Off\_d\left[V+1\right]\left[T+1\right]+K_{lrn}\times Tadj\_r\nu \times Tadj\_rt\times Tdif$$

Table_off_d [V] [T] is a value after learning on each map. On this occasion, [V] denotes an axis point of the battery voltage Vb, and [T] denotes an axis point of the target injector valve opening period Ttgt. In addition, Tadj_rv is a difference between the battery voltage Vb under an operating condition used for the learning and the axis point of the learning map. Tadj_rt is a difference between the target injector valve opening period Ttgt under the operating condition used for the learning and the axis point of the learning map.

After the corresponding elements are calculated, whereby the learning map in the injector valve closing delay period learning value calculating unit 59 is updated, the processing is ended.

On the other hand, in step S04, when the injector valve closing delay period difference Tdif is determined to be out of the learning range Trange, that is, the determination in step S04 is "No", the processing is immediately terminated.

As described above, as in 5 1, the learning map is generated with two axes which are the target injector valve opening period Ttgt and the battery voltage Vb. This is because the operation of the injector 2 is changed by the influence of the battery voltage Vb. The valve opening period of the injector 2 is assumed to change by various factors and the learning can be performed for a plurality of learning axes. In addition to the above-mentioned axes, a differential pressure Pdif between a fuel pressure Fp and a cylinder pressure Pcyl may be used as other learning axes. On this occasion, the fuel pressure Fp is a pressure of the injector 2 supplied fuel. The fuel pressure Fp is measured by a fuel pressure sensor located at the injector 2 is provided. In addition, the cylinder pressure Pcyl means a pressure within a cylinder of the internal combustion engine. The cylinder pressure Pcyl may be measured directly by a cylinder pressure sensor provided on the cylinder or may be predicted from an intake pipe pressure detected from an intake air pressure sensor provided in an intake pipe or the like. When the differential pressure Pdif between the fuel pressure Fp and the cylinder pressure Pcyl is used, it is possible to respond to the change in the valve opening period of the injector 2 adapted learning due to the pressure within the injector, which is a factor that influences the operation of the injector in fuel injection, namely the fuel pressure of the injector 2 supplied fuel and the pressure outside the injector, namely the pressure within the cylinder of the internal combustion engine.

As a learning value to be reflected on the learning map, even if an error occurs in the detection of the valve closing timing, the influence of the error of the learning value can be lowered by using only the value within the learning area Trange set in advance for learning, as described above , In addition, a reflection coefficient may be used when the learning value is reflected. The generation of an operation variation caused by a rapid change in the learning value can be suppressed by using the reflection coefficient. Moreover, the characteristic of the valve closing delay period can be learned for each injector by storing the learning map for each injector in the storage device 91 for the engine, including a plurality of injectors, for example a multi-cylinder engine. In addition, it should be understood that a single learning map may be used in common for a large number of injectors without providing the learning map for each injector.

The learning adapted to various changes is made possible by using a plurality of learning axes of the learning map in this way. However, the capacity of the storage device is 91 limited and therefore the number of learning axes can be determined appropriately. According to the first Embodiment, the target injector valve opening period at least one learning axis and the number of axes may be one or more.

<Injector drive period calculating unit 60>

The injector drive period calculating unit 60 is configured, the power supply period with respect to the solenoid 12 in the power supply control unit 51 that is, the injector drive period Td_on based on the target injector valve opening period Ttgt, which is in the target injector valve opening period calculating unit 53 is detected in the injector valve opening delay period calculating unit 54 detected injector valve opening delay period T_on and detected in the post-learning injector valve closing delay period calculating unit 55 Nachlern injector valve closing delay period Tadj. 6 FIG. 15 is a diagram illustrating a relationship between the injector drive period Td_on, the injector valve opening period Ttgt, the injector valve opening delay period Ton, the post-injector valve closing delay period Tadj, the actual injector valve closing timing Tclose, the injector valve closing difference Tdif, and the injector valve closing period Tdif; Actual valve closing delay period Tadj_real.

In this configuration, even if a variation in the valve-closing characteristic of the injector by a production variation or a change in the time of the injector 2 is generated, the variation of the fuel injection amount by learning the injector valve closing delay period Tadj based on the detected injector valve closing timing Tclose and calculating the current supply period to the solenoid 12 be reduced in accordance with the post-learning injector valve closing delay period Tadj. In addition, even if the valve opening period of the injector 2 is changed, the variation of the fuel injection amount can be suppressed by associating the learning map of the post-learning injector valve closing delay period Tadj with the target injector valve opening period Ttgt and the battery voltage Vb.

Referring to a flow chart of 7 Now, a description will be given of a sequence overview of the processing by the control device 50 According to the first embodiment, namely, a control method for the internal combustion engine by the control device 50 , The processing in the flowchart of 7 is repeated in a calculation cycle that is advanced by the arithmetic processing device 90 is set, the software executes, namely a in the storage device 91 saved program.

In the power supply control step of S201, the power supply control unit leads 51 the power supply control processing of supplying power to the solenoid 12 of the injector 2 according to the drive period Td_on of the injector 2 by, calculated by the injector drive period calculating unit 60 , as described above.

Then, in an injector valve closing timing calculating step of step S202, the injector valve closing timing calculating unit performs 56 the processing of calculating the injector valve closing timing Tclose in the injector 2 , as described above.

In the injector-actual valve closing delay period calculating step of step S203, the injector-actual valve closing delay period calculating unit 57 performs the processing of calculating the injector-actual valve closing delay period Tadj_real based on the injector valve closing timing Tclose detected in step S202 and power supply starting timing separately stored Tstart and drive period Td_on off.

In an injector valve closing delay period difference calculation step of step S204, the injector valve closing delay period difference calculating unit 58 performs the processing of calculating the injector valve closing delay period difference Tdif based on the detected actual-injector valve closing delay period Tadj_real and the post-learning injector valve closing delay period Tadj, as described above , out.

In an injector valve closing delay period learning value calculation step of step S205, the injector valve closing delay period learning value calculating unit 59 executes processing of reflecting the injector valve closing delay period difference Tdif to the injector valve closing delay period learning map when the injector valve closing delay period difference Tdif falls within the learning range Trange , as described above.

The processing in step S202 to step S205 may not be executed every time this flowchart is executed, and may be such decimation processing to be performed once in a plurality of times. For example, this flowchart is usually executed for each fuel injection processing for each cylinder. However, each of the pieces of processing does not always have to be executed in steps S202 to S205. In other words, such a rate of the frequency of executing the processing in steps S202 to S205 that the processing in step S202 to step S205 is executed once when the execution of the processing in step S201 and step S206 to step S210 is repeatedly executed be set beforehand in such a manner that the processing in step S202 to step S205 is executed once when the execution of this flowchart is performed twice, the processing for only the cylinder concerned is performed during one cycle, and the processing in step S202 to step S205 is not executed until the engine stops once, the learning is determined to be completed while driving. When the decimation processing is executed, a workload can be reduced. Even if the number of revolutions of the motor increases, the control can be continued while suppressing the increase in the load, and even if a CPU having a low computing performance is used, the individual variation between the injectors can be effectively learned.

In a target injection amount calculating step of step S206, the target injection amount calculating unit performs 52 the processing of calculating the target fuel injection amount to achieve the preset target air-fuel ratio based on the operating state of the internal combustion engine.

In the target injector valve opening period calculation step of step S207, the target injector valve opening period calculating unit performs 53 as described above, the processing of using the characteristic data of the injector valve opening period in advance in the ROM of the storage device 91 stored target fuel injection amount based on the fuel injection amount, which by the target injection amount computing unit 52 is calculated to calculate the target injector valve opening period Ttgt.

In an injector valve opening delay period calculating step of step S208, the injector valve opening delay period calculating unit performs 54 As described above, the processing of using the characteristic data at the injector valve opening delay period in advance in the ROM of the storage device 91 stored injector valve opening period to calculate the injector valve opening delay period TON.

In a post-learning injector valve closing delay period calculating step of step S209, the post-learning injector valve closing delay period calculating unit 55 performs the processing of calculating the post-injector valve closing delay period Tadj from the result of the injector valve opening delay period learning value, as described above to the injector valve opening period to which the learning result of the injector valve closing delay period learning value calculating unit 59 included in the learning map of the RAM of the storage device 91 is stored based on the target injector valve opening period Ttgt.

In an injector drive period calculating step of step S210, the injector drive period calculating unit performs 60 the processing of calculating the current supply period to the solenoid 12 in the power supply control unit 51 from, namely the drive period of the injector 2 based on the current supply period of the solenoid 12 That is, the target injector valve opening period Ttgt, which is the driving period of the injector 2 , the injector valve opening delay period Ton and the post-learning injector valve closing delay period Tadj.

The current supply period of the solenoid 12 is corrected by carrying out the above-mentioned processing, whereby the individual variation of the injector 2 caused fuel injection quantity variation is lowered.

As described above, in the control device 50 According to the first embodiment, the feedback control is executed so that the actual injector valve opening period reaches the target injector valve opening period by learning as the injector valve closing delay period characteristic corresponding to the target injector valve opening period, the difference between the target injector Valve opening period calculated injector valve closing delay period and the detected actual injector valve closing delay period in accordance with the target injector valve opening period characteristic, the target injection amount of the injector 2 corresponds, and the injector valve closing Delay period characteristic corresponding to the target injector opening period, whereby the power supply period of the actually operated solenoid, namely the injection pulse width, is corrected. Thus, the variation of the fuel injection amount becomes due to the individual variation of the injector 2 in, for example, the weights and clearances of the spring, the spool and the needle of the injector 2 and the individual variation in the injector 2 lowered due to secular change, thereby enabling the increase in the control accuracy of the fuel injection amount.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2013/191267 A1 [0003, 0006, 0032]

Claims (8)

An injector control device configured to control an injector, wherein the injector (2) includes: a fuel passage configured to allow a fuel to be injected for an internal combustion engine to pass; a needle valve (11) configured to separate from a valve seat (10) provided at a fuel injection port of the fuel passage to open the fuel passage and to abut against the valve seat (10) to close the fuel passage; and a solenoid (12) configured to attract the needle valve (11) in a valve opening direction when a current is supplied to the solenoid (12), the injector control device (50) comprising: a target injection amount calculating unit configured to calculate a target injection amount of the fuel injected by the injector in response to an operating state of the internal combustion engine; a target injector valve opening period calculating unit configured to calculate a target injector valve opening period corresponding to the target injection amount based on the target injection amount, in accordance with characteristic data on an injector valve opening period with respect to a fuel injection amount; an injector valve opening delay period calculating unit configured based on the target injector valve opening period, a valve opening delay period from a power supply start timing of the solenoid to a valve opening timing to which the valve seat and the needle valve (11) the injector (2) separate from each other to calculate, in accordance with characteristic data of the valve opening delay period with respect to the injector valve opening period; a post-learning injector valve closing delay computing unit (55) configured, based on the target injector valve opening period, a valve closing delay period from a power supply end timing of the solenoid to a valve closing timing to which the valve seat (10) and the needle valve (11) abutting the injector (2) in accordance with a learning map having the injector valve opening period as at least one axis and storing a learned value of the valve closing delay period; an injector drive period calculating unit (60) configured to calculate a current supply period of the solenoid (12) based on the target injector valve opening period, the valve opening delay period and the valve gate delay period; a power supply control unit configured to supply the current to the solenoid of the injector in accordance with the power supply period to the solenoid thereby to drive the injector; an injector valve closing timing calculating unit (56) configured to detect an actual valve closing timing to which the valve seat (10) and the needle valve (11) actually abut each other, based on a driving voltage waveform of the solenoid (12), when the power supply control unit (51) drives the injector based on the current supply period of the solenoid (12); an injector actual valve closing delay period calculating unit (57) configured to calculate an actual valve closing delay period from the power supply end timing of the solenoid (12) to the actual valve closing timing based on the actual valve closing timing, an actual power supply starting timing Solenoids (12) and an actual power supply period to the solenoid (12); an injector valve closing delay period difference calculating unit (58) configured to calculate a valve closing delay period difference which is a difference between the valve closing delay period calculated by the post-learning injector valve closing delay period calculating unit (55) actual valve closing delay period calculated by the injector valve closing timing calculation unit (56); and an injector valve closing delay period learning value calculating unit (59) configured to update the learned value of the valve closing delay period in the learning map based on the valve closing delay period difference, wherein the post-learning injector-valve-closing delay period calculating unit (55) is configured to use, at a next calculation timing, the learning map in which the learned value of the valve-closing updated by the injector-valve-closing delay period learning value calculating unit (59) Delay period is thereby stored to thereby calculate the valve closing delay period. Injector control device according to Claim 1 wherein the injector valve closing delay period learning value calculating unit (59) is configured to update the learning value when the valve closing delay period difference calculated by the injector valve closing delay period difference calculating unit (58) falls within a predetermined range. Injector control device according to Claim 1 or 2 wherein the injector valve closing delay period learning value calculating unit (59) is configured to use a predetermined reflection coefficient to update the learning value in the learning map when the learning value is updated. Injector control device according to one of Claims 1 to 3 wherein: the injector (2) comprises a plurality of injectors; and the learning map is provided for each of the plurality of injectors. The injector control apparatus according to claim 1, further comprising a battery voltage detection unit configured to detect a battery voltage of the internal combustion engine, wherein the learning map is configured to store the learning value while controlling the injector valve opening period and the battery voltage Has axes. Injector control device according to one of Claims 1 to 5 , further comprising: a fuel pressure calculating unit configured to perform detection or calculation of a pressure of the fuel supplied to the injector (2); and a cylinder pressure calculating unit configured to perform detection or calculation of pressure within a cylinder of the internal combustion engine into which the fuel is injected, wherein the learning map is configured to store the learning value while maintaining a differential pressure between the pressure of the fuel Fuel pressure computing unit and the pressure within the cylinder from the cylinder pressure computing unit has as a further axis. Injector control device according to one of Claims 1 to 6 wherein a number of times of executing each of the parts of the processing of the injector valve closing timing calculating unit (56), the injector actual valve closing delay period calculating unit (57), the injector valve closing delay period difference calculating unit (58) and the injector valve closing delay period Learning value calculating unit (59) is set in advance to a ratio of one to a plurality of times of executing the processing of the power supply control unit (51). An injector control method for controlling an injector, wherein the injector (2) includes: a fuel passage configured to allow a fuel to be injected for an internal combustion engine to pass; a needle valve (11) configured to separate from a valve seat (10) provided at a fuel injection port of the fuel passage to open the fuel passage and to abut against the valve seat (10) to close the fuel passage; and a solenoid configured to attract the needle valve in a valve opening direction when a current is supplied to the solenoid, the injector control method comprising: a target injection amount calculating step of calculating a target injection amount of the fuel injected by the injector (2) in response to an operating state of the internal combustion engine; a target injector valve opening period calculating step (S207) of calculating, based on the target injection amount, a target injector valve opening period corresponding to the target injection amount, in accordance with characteristic data on an injector valve opening period with respect to a fuel injection amount; an injector valve opening delay period calculating step (S208) of calculating, based on the target injector valve opening period, a valve opening delay period from a current supply start timing of the solenoid to a valve opening timing to which the valve seat (10) and the needle valve (11) of the injector (2) disconnect from each other in accordance with characteristic data on the valve opening delay period with respect to the injector valve opening period; a post-learning injector valve closing delay period calculating step (S209) of calculating, based on the target injector valve opening period, a valve closing delay period from a current supply end timing of the solenoid to a valve closing timing to which the valve seat (10) and the needle valve (10) 11) of the injector (2) abut each other in accordance with a learning map having the injector valve opening period as at least one axis and storing a learned value of the valve closing delay period; an injector drive period calculating step (S210) of calculating a current supply period of the solenoid (12) based on the target injector valve opening period, the valve opening delay period, and the valve-shake delay period; a power supply control step (S201) of supplying the current to the solenoid (12) of the injector (2) in accordance with the power supply period to the solenoid to thereby drive the injector (2); an injector valve closing timing calculating step (S202) of detecting an actual valve closing timing to which the valve seat (10) and the needle valve (11) actually abut, based on a driving voltage waveform of the solenoid (12) when the injector (2) in the power supply control step (S201) is driven based on the current supply period of the solenoid (12); an injector actual valve closing delay period calculating step (S203) of calculating an actual valve closing delay period from the power supply end timing of the solenoid (12) to the actual valve closing timing, based on the actual valve closing timing, an actual power supply starting timing of the solenoid (12), and an actual power supply period to the solenoid (12); an injector valve closing delay period difference calculating step (S204) of calculating a valve closing delay period difference which is a difference between the valve closing delay period calculated in the post-injector valve closing delay period calculating step (S209) and the injector valve closing timing calculating step (S202) is the actual valve closing delay period calculated; and an injector valve closing delay period learning value calculating step (S205) of updating the learned value of the valve closing delay period in the learning map based on the valve closing delay period difference, wherein the post-learning injector valve closing delay period calculating step (S209) using, at a next calculation timing, the learning map in which the learned value of the valve closing delay period updated in the injector valve closing delay period learning value calculating step (S205) is stored to thereby calculate the valve closing delay period.

Images